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Sunday, October 17, 2010

Dealing With Diarrhoeal Diseases, by Nomad Medic

Escherichia coli - Scanning Electron Microscopy
The recent news of confirmed cases of cholera after the massive flooding in Pakistan highlights a potential threat that anyone could be faced with after a disaster. While cholera has been cited specifically, there are several other diarrhoeal diseases that have similar symptoms and can also kill. These include such pathogens as Rotavirus, Escherichia coli, Salmonella typhi (responsible for Typhoid Fever) and Shigellosis (dysentery).
These illnesses are responsible for a huge number of deaths every year. In fact, the World Health Organization (WHO) reports that there are approximately two billion cases annually. Diarrhoeal diseases account for the deaths of 1.5 million children in the same time period. The majority of these occur in developing countries where availability of clean water, food, and sanitation are limited. How many people reading this are preparing for a situation where you could have limited sanitation, food, or clean water?
The WHO defines diarrhoea as “the passage of 3 or more loose or liquid stools per day, or more frequently than is normal for the individual.” I think we are all familiar with this condition. These diseases are often accompanied by several other signs and symptoms including abdominal pain, fever, increased heart rate, and dizziness.  One of the most disturbing signs that may develop is blood in the stool. As unnerving as this is for the person experiencing it or the one caring for them, this symptom is not as dire as it may appear. In the presence of some of these ‘bugs’, this is part of the disease process and will resolve as the body fights the infection.
Many of these pathogens are ever-present in the world we live in. For example, the bacterium that causes cholera is commonly found in seawater. Outbreaks of these diseases occur when the reservoirs containing the offending pathogen are introduced into a population susceptible to them. After disasters people are often operating in high stress environments and suboptimal conditions. Their immune systems can be depressed to a point that the pathogens get a foothold when they are exposed.
This exposure typically happens via ingestion. This comes from contaminated water sources (i.e. floodwater in the water supply, poor latrine placement causing direct fecal contamination, etc.), contaminated food (under cooked or raw contaminated foods, shellfish from contaminated waters, etc.), or direct oral/fecal transmission (contaminated hands touching lips). Vectors such as flies that stop at the outhouse on the way to your toothbrush have also been cited.
The first and most key step to fighting these diseases is prevention. If we can avoid exposure to these pathogens, we avoid the disease. Depending on the situation, staying ‘Fit to fight’ could literally mean the difference between life and death. There are several points to preventing this though.
Foremost of these preventative steps is that water must be properly treated. While it is not in the scope of this article to go deeply into water purification techniques, I would like to mention a few points. First, start with the cleanest fresh water possible. Collecting from a moving source (i.e. a river or stream) is proffered over a standing source (i.e. a pond). Always try to filter out as many debris as you can. This includes sediments and silts. A study in Bangladesh found that simply filtering water through cloth decreased the incidence of cholera by 48%s. The cleaner the water you start with, the more effective your treatment efforts will be. Chlorination of water is an inexpensive method to treat water as long as you have the supplies available. There are many consideration that must be taken into account when deciding on what amount and what form (liquid versus powdered) to store chlorine in. (Home generation if chlorine is also an option that is used in some parts of the world) As a quick review, the general principal in using unscented liquid chlorine bleach is to use 2 drops of bleach per quart (.5l) of water, 8 drops of bleach per gallon (3.8L) of water, and 1/2 teaspoon (2.5ml) bleach per five gallons of water. Allow to stand for 30 minutes before use. If water is cloudy, double the recommended dosages of bleach. Testing kits, such as used for pools, can be used to monitor the chlorine levels. These should be 1mg/l at storage points, (i.e. piped in cisterns) but .2-.5mg/l at the point of consumption. If you can taste the chlorine, it is over .8 mg/l. The most available means of water treatment may very well be boiling. The principal of starting with the cleanest water available applies as above.  Per the Centers for Disease Control and Prevention (CDC), at sea level water should be brought to a rolling boil and kept there for one minute. At altitudes above 6,562 feet (2,000 m) this needs to be increased to three minutes. Water filter units that rely on mechanical filtering only are generally not adequate to filter out all the pathogens that cause diarrhoeal diseases. Check the manufactures statistics or use a chemical treatment after filtering to be sure. We all understand that we must have water; make sure the water you drink is safe.
The CDC has for years pushed the statement "Boil it, cook it, peel it, or forget it" in regards to eating while abroad. This is intended to directly fight cholera and the similar diseases. Foods must be thoroughly cooked to kill potential pathogens. Most bad bugs are killed when they are brought above 160F (70C) but some must reach boiling at 212F (100C) and held at that temperature for 15 minutes. This is all parts of the food item. That point becomes very important when cooking large pieces of meat or thick stews. Holding food at a temperature where it is literally  ‘steaming hot’ (140F or 60C) and never allowing food to set at room temperature for more than two hours will continue to protect you from illness. All this requires that you can prepare food yourself. Consider this another reason on what should be a long list of reasons to store food. If you are in a food line, soup kitchen, of refugee camp, you have no control over these facts. When it comes to raw foods, use treated water to wash them though cooking is a better way to ensure safety. The ‘peel it’ point is pretty self explanatory; peels and shells protect the parts you eat. Pathogenic bacteria can find their way to your foods. Take steps to ensure any contaminates are rendered safe before you ingest them.
Proper sanitation is key to preventing the spread of these diseases. The #1 most important task in regard to this is frequent hand washing. Ideally this would be done with hot water and soap. Homemade soaps, wood ash, or even the simple mechanical action of scrubbing your hands in clean flowing water will help. Trimming fingernails reduces areas that can trap pathogens. As previously mentioned, insects and other vermin can spread these diseases. Proper steps such as covering latrines, pest mitigation, and the use of insect repellents are necessary. Keep the pathogens away from potential host and you solve the problem.
If people are suffering with any of these conditions, they should be separated from the healthy. Caregivers need to religiously wash their hands before and after contact with these patients. This isolation will decrease the spread of the disease. All waste, clothing, and bedding, from these patients is potentially a source of further infection and must be treated as such. A solution using 1 tablespoon (15ml) chlorine solution per gallon (3.8L) of water can be sprayed on surfaces to disinfect them. Clothing and linens need to be well washed, preferably in hot water with bleach. Exposure to sunlight has been shown to kill many bacteria and viruses. Hanging this clean linen to dry in the sun can also help kill remaining pathogens. There are many reasons the average life expectancy has increased so significantly over the last 100 years. A better understanding of the relation of sanitary and hygienic practices to overall health is not the least of them.
All of these diseases usually respond very well to oral rehydration. Per the CDC ‘With prompt rehydration, fewer than 1% of cholera patients die.’ Fluids should be given as soon as the patient can take them. These should be taken as frequent small amounts as opposed to large volumes at once. The liquid of choice is water with oral rehydration solution added. The commercial versions of this solution contain a plethora of electrolytes, vitamins, and minerals. They are available from many different suppliers and come in a range of flavors. Recipes for making your own abound but this version is common. To 5 cups (~1L) of clean water add 8 teaspoons of sugar and 1 teaspoon of salt. Mix well and have the patient sip slowly. This simple formula is safe and effective though the flavor isn’t anything to write home about. It may be beneficial to add a small amount of powdered drink mix to improve the flavor, especially for children. It is important to not increase the overall sugar levels in this solution by much as this can lead to further dehydration. Other recipes will add sodium bicarbonate (baking soda) and/or NoSalt (potassium chloride). Intravenous rehydration may be needed and should be undertaken using Normal Saline (.9% Sodium Chloride) or Lactated Ringers (Hartman’s Solution). In a PAW, I’d personally reserve IV fluids for other cases if at all possible. Aggressive treatment with oral solutions should preclude the need for an IV infusion. ‘Safe’ food should continue to be offered to the patient though its importance is much less than that of water. Avoid foods such as dairy products, greasy items, or any that cause gas. In these diarrhoeal diseases, it is dehydration that causes death. By staying ahead of the fluids lost, this can be prevented and thus save the patient’s life.
Other medications that may prove useful in cholera or other like diseases are antibiotics. These should be used sparingly and only in severe cases. Due to the development of resistant strains, the most commonly recommended antimicrobial is Ciprofloxacin 500mg twice a day (children should be dosed by weight 15 mg/kg). Acetaminophen (Paracetamol) may be used to combat fever though utilizing the minimizing effective dose will spare the liver some hardship. Anti-diarrhoeal medications such as loperimide (Imodium) should be avoided in severe diarrhoea. Over-use of these medications can lead to a life threatening condition known as toxic megacolon which is just as bad as it sounds. With any medication, be well versed in the contraindications and side effects before you use them. As previously stated, these patients respond well to rehydration and this is the area treatment should be concentrated on.
Cholera, typhoid fever, a dysentery have a well earned reputation as mass murderers. During the American Civil War “The Union army reported that more than 995 out of every 1,000 men eventually contracted chronic diarrhea or dysentery during the war; the Confederates fared no better.” These killers have made appearances in every major conflict to one extent or another as far back as man has recorded history. They crop up during floods, landslide, hurricanes, and other emergencies where ‘basic’ services are interrupted. Armed with a bit of knowledge and by practicing the proverbial ounce of prevention, we can overcome these obstacles.
As with any medical advice, I highly recommend you cross reference anything you read before you use it.